1. Field of the Invention
This invention refers to a constructive form of a reaction rod to be applied to the suspension system of automotive vehicles, more specifically, to heavy vehicles provided with pneumatic or mixed suspension systems.
2. Description of Related Art
The reaction rods of the vehicular suspension systems are composed, basically, of a box with a housing in its interior, of cylindrical or spherical shape, in which is inserted a pin provided with a segment also of cylindrical or spherical shape, where vulcanized rubber is provided in the interior housing of the box. After the insertion of the pin with vulcanized rubber in the interior housing of the box, the pin is fixed with retaining rings that prevent its lateral displacement, resulting in a joint, called molecular joint. The box of the molecular joint is provided on the end of a bar that is fixed to the chassis of the vehicle, being that the pin with vulcanized rubber placed in its interior, has opposite extensions that are projected towards the outside of the box, to be fixed to the shaft of the vehicle. The system aims to maintain the projected geometry of the shaft relative to the chassis.
The above described fixing may if desired be inverted, but with the same purpose of maintaining the projected geometry of the shaft relative to the chassis. The molecular joint of the reaction rod provides to the shaft, when it is operating, radial, angular and rotational movements, relative to the box, but always returning it to its original assembling position when the operational effort is relieved. These reaction rods to the shaft, however, need a load of displacement progressively greater when the displacement effort of the shaft is lateral relative to the chassis. This progressiveness must occur in the proportion that the shaft is displaced laterally and this from its central position until the lateral limit of displacement.
To obtain this effect, the state of the art applied to the center of the interior housing of the box, and to its entire circumference, a recess or channel created by a machining process that provides to the vulcanized rubber on the ball or cylindrical type pin a relief of the displacement load, when the same is in its original assembling position, that is, centered. Having in view that the lateral walls of the interior housing of the box, through which are projected the ends of the ball or cylindrical pin, do not have this recess or channel, a result is that the system causes a smaller displacement effort to the short radial and angular-lateral movements, resulting that this effort progressively increased in the proportion that the lateral angularity of the displacement increases. In this manner, the targeted objective of establishing a progressive increase of load so as to resist to the effort of lateral displacement of the shaft relative to the chassis is attained.
However, in spite of being efficient in the desired effect, this construction set forth in the state of the art presents certain complexities and involves high costs in the manufacturing process, loss of material, etc.
The objective of this invention is to eliminate these inconveniences by providing to the system a simple and low cost construction, besides making possible construction variants that produce the effect of progressiveness of load in specific angles of the shaft, as desired in the project of the vehicle.
To attain this objective, this invention provides the usual machining in the interior housing of the reaction rod box, without any recess or central channel, but produces the requisite relief, through a recess or channel in the vulcanized rubber itself, to the ball or cylinder type pin, during the injection of the same. This construction system processes the recess or channel of the very injection mold of the rubber that is vulcanized in the pin, so as to obtain the piece ready for mounting in the injection process itself. Moreover, if it is desirable, pursuant to the project of the vehicle, that the progressive effort of lateral displacement occurs in specific angles of the shaft, this effect also is easily obtained by providing the injection mold with segments of recess or channels only at the points at which the relief is desired.